This invention relates to electrochemical processes and to electrochemical cells and more particularly, but not exclusively, is concerned with electrochemical processes and electrochemical cells employing particulate electrodes.
Some electrochemical cells, for example those where one of the electrodes is a fluidised bed electrode, have separate anode and cathode compartments, separated by a common ion-permeable wall, for example a semi-permeable wall. This ion-permeable wall is intended to prevent passage of solid particles and/or of specific species of ions from one compartment to the other. Further, it is often desired that the anolyte present in an anode compartment and the catholyte present in a cathode compartment be kept separate. More generally, it is often desirable to employ in separate electrode compartments electrodes of widely differing types. The nature of the electrodes may be so different that a significant pressure difference develops across the whole or part of the common ion-permeable wall; if formed from a delicate membrane, for example a semi-permeable membrane, the pressure difference is often sufficient to rupture the membrane.